linux_aura: Fix close button in left positioned maximized windows.

This fixes some calculations in the OpaqueBrowserFrameViewLayout and
also makes IamgeButton place mirrored ALIGN_RIGHT images correctly.

BUG=317482
R=sky@chromium.org

Review URL: https://codereview.chromium.org/68643003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234625 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234625